Thorium targets were irradiated with 438-MeV protons, resulting in spallation and high-energy fission reactions. The measured production cross sections of 38 nuclides in the mass range 83 to 233 are reported. These cross-section data are useful for validating nuclear interaction models and are compared to simulated cross sections calculated using three different Monte Carlo packages, fluka (version 2011.2x.7), geant4 (version 10.6, with the Liege intranuclear cascade model and the abla version 3.1 evaporation code), and geant4 (version 10.6, with the binary cascade model). These data are also useful for estimating radionuclide production yields following an irradiation, in particular for the production of ${}^{225}\mathrm{Ac}$, a radionuclide of currently heightened interest in nuclear medicine for the treatment of cancer. For most nuclides reported, the measured, literature, and simulated cross-section values agree within a factor of 2.

The drag and diffusion coefficients are studied within the framework of Fokker-Planck dynamics for the case of a charm quark propagating in an expanding quark-gluon plasma. The space-time evolution of the nuclear matter created in the relativistic heavy-ion collision is modeled using music, a $3+1\mathrm{D}$ relativistic viscous hydrodynamic approach. The effect of viscous corrections to the heavy quark transport coefficients is explored by considering scattering processes with thermal quarks and gluons in the medium. It is observed that the momentum diffusion of the heavy quarks is sensitive to the shear and bulk viscosity to entropy ratios. The collisional energy loss of the charm quark in the viscous quark-gluon plasma is analyzed.

This paper presents isolated photon-hadron correlations using $pp$ and $p$-Pb data collected by the ALICE detector at the LHC. For photons with $\left|\eta \right|<0.67$ and $12<p_{\mathrm{T}}<40$ GeV/$c$, the associated yield of charged particles in the range $\left|\eta \right|<0.80$ and $0.5<p_{\mathrm{T}}<10$ GeV/$c$ is presented. These momenta are much lower than previous measurements at the LHC. No significant difference between $pp$ and $p$-Pb is observed, with Pythia 8.2 describing both data sets within uncertainties. This measurement constrains nuclear effects on the parton fragmentation in $p$-Pb collisions, and provides a benchmark for future studies of Pb-Pb collisions.

We use a Bayesian inference analysis to explore the sensitivity of Taylor expansion parameters of the nuclear equation of state (EOS) to the neutron star dimensionless tidal deformability ($\mathrm{\Lambda }$) on 1- to 2-solar-mass neutron stars. A global power law dependence between tidal deformability and the compactness parameter ($M/R$) is verified over this mass region. To avoid superfluous correlations between the expansion parameters, we use a correlation-free EOS model based on a recently published metamodeling approach. We find that assumptions in the prior distribution strongly influence the constraints on $\mathrm{\Lambda }$. The $\mathrm{\Lambda }$ constraints obtained from the neutron star merger event GW170817 prefer low values of $L_{\text{sym}}$ and $K_{\text{sym}}$, for a canonical neutron star with 1.4 solar masses. For a neutron star with mass $<1.6$ solar masses, $L_{\text{sym}}$ and $K_{\text{sym}}$ are highly correlated with the tidal deformability. For more massive neutron stars, the tidal deformability is more strongly correlated with higher order Taylor expansion parameters.

The magnetic field of a rotating pulsar might be so strong that the equation of state (EOS) of neutron star (NS) matter is significantly affected by the spin polarization of baryons. In the present work, the EOS of the spin-polarized nuclear matter is investigated in the nonrelativistic Hartree-Fock formalism, using a realistic density-dependent nucleon-nucleon interaction with its spin- and spin-isospin dependence accurately adjusted to the Brueckner-Hartree-Fock results for spin-polarized nuclear matter. The nuclear symmetry energy and proton fraction are found to increase significantly with increasing spin polarization of baryons, leading to a larger probability of the direct Urca process in the cooling of magnetar. The EOS of the $\beta$-stable $\mathrm{np}e\mu$ matter obtained at different spin polarizations of baryons is used as the input for the Tolman-Oppenheimer-Volkoff equations to determine the hydrostatic configuration of NS. Based on the GW170817 constraint on the radius $R_{1.4}$ of NS with $M\approx 1.4M_{\odot }$, our mean-field results show that up to $60\%$ of baryons in the NS merger might be spin-polarized. This result supports the magnetar origin of the “blue” kilonova ejecta of GW170817 suggested by Metzger et al., and the spin polarization of baryons needs, therefore, to be properly treated in the many-body calculation of the EOS of NS matter before comparing the calculated NS mass and radius with those constrained by the multimessenger GW170817 observation.

A projectile Coulomb-excitation experiment was performed at the radioactive-ion beam facility HIE-ISOLDE at CERN to obtain $E2$ and $M1$ transition matrix elements of ${}^{140}\mathrm{Nd}$ using the multistep Coulomb-excitation code gosia. The absolute $M1$ strengths, $\mathrm{B}(M1;2_2^{+}\to 2_1^{+})=0.033\left(8\right){\mu }_{\mathrm{N}}^2,\mathrm{B}(M1;2_3^{+}\to 2_1^{+})=0.{26}_{-0.10}^{+0.11}{\mu }_{\mathrm{N}}^2$, and $\mathrm{B}(M1;2_4^{+}\to 2_1^{+})<0.04{\mu }_{\mathrm{N}}^2$, identify the $2_3^{+}$ state as the main fragment of the one-quadrupole-phonon proton-neutron mixed-symmetry state of ${}^{140}\mathrm{Nd}$. The degree of $F$-spin mixing in ${}^{140}\mathrm{Nd}$ was quantified with the determination of the mixing matrix element $V_{\mathrm{F}-\mathrm{mix}}<7_{-7}^{+13}\mathrm{keV}$.

In this work we present dipole scattering amplitudes, including the dependence on the impact-parameter, for a variety of nuclear targets of interest for the electron-ion colliders (EICs) being currently designed. These amplitudes are obtained by numerically solving the Balitsky-Kovchegov equation with the collinearly improved kernel. Two different cases are studied: initial conditions representing the nucleus under consideration and the solutions based on an initial condition representing a proton complemented by a Glauber-Gribov prescription to obtain dipole-nucleus amplitudes. We find that the energy evolution of these two approaches differ. We use the obtained dipole scattering amplitudes to predict ($\mathrm{i}$) nuclear structure functions that can be measured in deep-inelastic scattering at EICs and ($\mathrm{ii}$) nuclear suppression factors that reveal the energy evolution of shadowing for the different cases we studied. We compare our predictions with the available data.

Background: High-spin isomers at $\approx 9$ MeV excitation energies have been reported in several $N=83$ isotones near $Z=64$. Spin and parity assignments of $J^{\pi }=49/2^{+}$ remain tentative for a number of these states in the odd-$A$ nuclei.

Purpose: To study the decay of the ($49/2^{+}$) high-spin isomer in ${}^{145}\mathrm{Sm}$, make firm spin and parity assignments to the isomer and states populated in its decay, and investigate the structure of the nucleus.

Methods: The ${}^{145}\mathrm{Sm}$ isomer was populated in the ${}^{124}\mathrm{Sn}({}^{26}\mathrm{Mg},5n)$ reaction. $\gamma$-ray and conversion-electron data were collected using the Solenogam array.

Results: A revised lifetime of $t_{1/2}=3.52\left(16\right)\mu \mathrm{s}$ was measured for the high-spin isomer. Several new states have been added to the level scheme, and a new state at 8815 keV is proposed as the isomer, based on decay-property systematics, transition strengths, and spin and parity assignments. Firm spin and parity assignments have been made to states up to and including the isomer and the new level scheme is interpreted using shell-model calculations performed with the KShell program.

Conclusions: The interpretation of the $49/2^{+}$ isomer as a deformed excitation of the core neutrons remains unchanged, although there has been a significant revision of the level scheme below the isomer, and hence significant reinterpretations of the lower-lying states.

The high-spin states in ${}^{130}\mathrm{Ba}$ have been investigated using the ${}^{122}\mathrm{Sn}({}^{13}\mathrm{C},5n)$ reaction and the GALILEO array coupled to the EUCLIDES and Neutron Wall ancillary detectors. The level scheme has been extended to an excitation energy of $\approx 12$ MeV and spin 28. Two sets of pseudospin partner bands have been identified built on $\pi h_{11/2}(g_{7/2},d_{5/2})$ and $\nu h_{11/2}(s_{1/2},d_{3/2})$ configurations. The assignments are supported by calculations using the projected shell model and the particle rotor model.

We present a measurement of the first-order azimuthal anisotropy $v_1$ of deuterons from $\text{Au}+\text{Au}$ collisions at $\sqrt{s_{NN}}=7.7$, 11.5, 14.5, 19.6, 27, and 39 GeV recorded with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The energy dependence of the $v_1\left(y\right)$ slope, $d{v}_1{/dy|}_{y=0}$, for deuterons, where $y$ is the rapidity, is extracted for semicentral collisions (10%–40% centrality) and compared with that of protons. While the $v_1\left(y\right)$ slopes of protons are generally negative for $\sqrt{s_{NN}}>10\mathrm{GeV}$, those for deuterons are consistent with zero, a strong enhancement of the $v_1\left(y\right)$ slope of deuterons is seen at the lowest collision energy (the largest baryon density) at $\sqrt{s_{NN}}=7.7\mathrm{GeV}$. In addition, we report the transverse momentum dependence of $v_1$ for protons and deuterons. The experimental results are compared with transport and coalescence models.

Background: The nuclear symmetry energy $E_{\mathrm{sym}}\left(\rho \right)$ encodes information about the energy necessary to make nuclear systems more neutron rich. It is currently poorly known especially at suprasaturation densities but has broad impacts on properties of neutron stars and on nuclear structure and reactions. While its slope parameter $L$ at the saturation density ${\rho }_0$ of nuclear matter has been relatively well constrained by recent astrophysical observations and terrestrial nuclear experiments, its curvature $K_{\mathrm{sym}}$ characterizing the $E_{\mathrm{sym}}\left(\rho \right)$ around $2{\rho }_0$ remains largely unconstrained. Over 520 calculations for $E_{\mathrm{sym}}\left(\rho \right)$ using various nuclear theories and interactions in the literature have predicted several significantly different $K_{\mathrm{sym}}\text{−}L$ correlations.

Purpose: If a unique $K_{\mathrm{sym}}\text{−}L$ correlation of $E_{\mathrm{sym}}\left(\rho \right)$ can be firmly established, it will enable us to progressively constrain the high-density behavior of $E_{\mathrm{sym}}\left(\rho \right)$ using the available and better constrained slope parameter $L$. We investigate if and by how much the different $K_{\mathrm{sym}}\text{−}L$ correlations may affect neutron star observables. We also examine if LIGO/VIRGO's observation of tidal deformability using gravitational waves from GW170817 and NICER's recent extraction of neutron star radius using high-precision x-rays can distinguish the different $K_{\mathrm{sym}}\text{−}L$ correlations predicted.

Methods: A metamodel of nuclear equations of state (EOSs) with three representative $K_{\mathrm{sym}}\text{−}L$ correlation functions is used to generate multiple EOSs for neutron stars. We then examine effects of the $K_{\mathrm{sym}}\text{−}L$ correlation on the crust-core transition density and pressure as well as the radius and tidal deformation of canonical neutron stars.

Results: We found that the $K_{\mathrm{sym}}\text{−}L$ correlation affects significantly both the crust-core transition density and pressure. It also has strong imprints on the radius and tidal deformability of canonical neutron stars, especially at small $L$ values. The available data from LIGO/VIRGO and NICER set some useful limits for the slope $L$ but cannot distinguish the three representative $K_{\mathrm{sym}}\text{−}L$ correlations considered.

Conclusions: The $K_{\mathrm{sym}}\text{−}L$ correlation is important for understanding properties of neutron stars. More precise and preferably independent measurements of the radius and tidal deformability from multiple observables of neutron stars have the strong potential to help pin down the curvature-slope correlation and thus the high-density behavior of nuclear symmetry energy.

We present calculations of the bulk properties and multiparticle correlations in a large variety of collision systems within a hybrid formalism consisting of impact-parameter-dependent Glasma initial conditions, music viscous relativistic hydrodynamics, and urqmd microscopic hadronic transport. In particular, we study heavy ion collisions at the Large Hadron Collider (LHC), including $\text{Pb}+\text{Pb}$, $\text{Xe}+\text{Xe}$, and $\text{O}+\text{O}$ collisions, and $\text{Au}+\text{Au}$, $\text{U}+\text{U}$, $\text{Ru}+\text{Ru}$, $\text{Zr}+\text{Zr}$, and $\text{O}+\text{O}$ collisions at the Relativistic Heavy Ion Collider (RHIC). We further study asymmetric systems, including $p+\text{Au}$, $d+\text{Au}$, ${}^3\mathrm{He}+\text{Au}$, and $p+\text{Pb}$ collisions at various energies as well as $p+p$ collisions at 0.5 and 13 TeV. We describe experimental observables in all heavy ion systems well with one fixed set of parameters, validating the energy and system dependence of the framework. Many observables in the smaller systems are also well described, although they test the limits of the model. Calculations of $\text{O}+\text{O}$ collisions provide predictions for potential future runs at RHIC and the LHC.

We propose a new regularization scheme to study the bound state of two-nucleon systems in lattice effective field theory. Inspired by a continuum effective field theory calculation, we study an exponential regulator acting on the leading-order and next-to-leading order interactions, consisting of local contact terms. By fitting the low-energy coefficients to deuteron binding energy and the asymptotic normalization coefficient on a lattice simulation, we extract the effective range expansion (ERE) parameters in the ${}^3{S}_1$ channel to order $p^2$. We explore the impact of different powers of the regulator on the extracted ERE parameters for the lattice spacing $a=1.97$ fm. Moreover, we investigate how the implementation of the regularization scheme improves the predicted ERE parameters on the lattice spacing in the range of $1.4\le a\le 2.6\mathrm{fm}$. Our numerical analysis indicates that for lattice spacing greater than $2\mathrm{fm}$, the predicted observables are very close to the experimental data.

We have performed an exclusive measurement of the $K^{-}+{}^3\mathrm{He}\to \mathrm{\Lambda }pn$ reaction at an incident kaon momentum of $1\mathrm{GeV}/c$. In the $\mathrm{\Lambda }p$ invariant mass spectrum, a clear peak was observed below the mass threshold of $\overline{K}+N+N$, as a signal of the kaonic nuclear bound state, $\overline{K}NN$. The binding energy, decay width, and $S$-wave Gaussian reaction form factor of this state were observed to be $B_K=42\pm 3{\left(\mathrm{stat}.\right)}_{-4}^{+3}\left(\mathrm{syst}.\right)\mathrm{MeV}, {\mathrm{\Gamma }}_K=100\pm 7{\left(\mathrm{stat}.\right)}_{-9}^{+19}\left(\mathrm{syst}.\right)\mathrm{MeV}$, and $Q_K=383\pm 11{\left(\mathrm{stat}.\right)}_{-1}^{+4}\left(\mathrm{syst}.\right)\mathrm{MeV}/c$, respectively. The total production cross section of $\overline{K}NN$, determined by its $\mathrm{\Lambda }p$ decay mode, was ${\sigma }_K^{\mathrm{tot}}B{R}_{\mathrm{\Lambda }p}=9.3\pm 0.8{\left(\mathrm{stat}.\right)}_{-1.0}^{+1.4}\left(\mathrm{syst}.\right)\mu \mathrm{b}$. We estimated the branching ratio of the $\overline{K}NN$ state to the $\mathrm{\Lambda }p$ and ${\mathrm{\Sigma }}^{0}p$ decay modes as $B{R}_{\mathrm{\Lambda }p}/B{R}_{{\mathrm{\Sigma }}^{0}p}\sim 1.7$, by assuming that the physical processes leading to the $\mathrm{\Sigma }NN$ final states are analogous to those of $\mathrm{\Lambda }pn$.

In the present work, we build a bridge between the $\alpha$ decay energy and the $\alpha$-particle preformation factor, and put forward an analytic formula for estimating the $\alpha$-particle preformation factor. With the help of this formula, experimental $\alpha$ decay half-lives of 535 nuclei varying from $6.90\times {10}^{-8}$ to $6.34\times {10}^{26}$ s are reproduced within a factor of 1.81. Noticeably, for superheavy nuclei, calculated $\alpha$ decay half-lives can well reproduce experimental data and reduce the deviations significantly. This formula can be applied to estimate the $\alpha$-particle preformation factors and predict the $\alpha$ decay half-lives for unsynthesized superheavy nuclei, which would be useful for future experiments in synthesizing new superheavy elements and isotopes. This formula can shed light on microscopic nuclear structure information such as shell and odd-even staggering effects, and provide a positive signal for the existence of an island of stability for superheavy nuclei.

The neutron skin thickness $\mathrm{\Delta }{r}_{np}$ in heavy nuclei was known as one of the most sensitive terrestrial probes of the nuclear symmetry energy $E_{\mathrm{sym}}\left(\rho \right)$ around $\frac{2}{3}$ of the saturation density ${\rho }_0$ of nuclear matter. Existing neutron skin data mostly from hadronic observables suffer from large uncertainties and their extraction from experiments are often strongly model dependent. While waiting eagerly for the promised model-independent and high-precision neutron skin data for ${}^{208}\mathrm{Pb}$ and ${}^{48}\mathrm{Ca}$ from the parity-violating electron scattering experiments (PREX-II and CREX at JLab as well as MREX at MESA), within the Bayesian statistical framework using the Skyrme-Hartree-Fock model we infer the posterior probability distribution functions (PDFs) of the slope parameter $L$ of the nuclear symmetry energy at ${\rho }_0$ from imagined $\mathrm{\Delta }{r}_{np}\left({}^{208}\mathrm{Pb}\right)=0.15$, 0.20, and 0.30 fm with a $1\sigma$ error bar of 0.02, 0.04, and 0.06 fm, respectively, as well as $\mathrm{\Delta }{r}_{np}\left({}^{48}\mathrm{Ca}\right)=0.12$, 0.15, and 0.25 fm with a $1\sigma$ error bar of 0.01 and 0.02 fm, respectively. The results are compared with the PDFs of $L$ inferred using the same approach from the available $\mathrm{\Delta }{r}_{np}$ data for ${}^{116,118,120,122,124,130,132}\mathrm{Sn}$ from hadronic probes. They are also compared with results from a recent Bayesian analysis of the radius and tidal deformability data of canonical neutron stars from GW170817 and NICER. The neutron skin data for Sn isotopes gives $L=45.5_{-21.6}^{+26.5}$ MeV surrounding its mean value or $L=53.4_{-29.5}^{+18.6}$ MeV surrounding its maximum a posteriori value, respectively, with the latter smaller than but consistent with the $L={66}_{-20}^{+12}$ MeV from the neutron star data within their 68% confidence intervals. We found that $\mathrm{\Delta }{r}_{np}=0.17$–0.18 fm in ${}^{208}\mathrm{Pb}$ with an error bar of about 0.02 fm leads to a PDF of $L$ compatible with that from analyzing the Sn data. To provide additionally useful information on $L$ extracted from the $\mathrm{\Delta }{r}_{np}$ of Sn isotopes, the experimental error bar of $\mathrm{\Delta }{r}_{np}$ in ${}^{208}\mathrm{Pb}$ should be at least smaller than 0.06 fm aimed by some current experiments. In addition, the $\mathrm{\Delta }{r}_{np}\left({}^{48}\mathrm{Ca}\right)$ needs to be larger than 0.15 fm but smaller than 0.25 fm to be compatible with the Sn and/or neutron star results. To further improve our current knowledge about $L$ and distinguish its PDFs in the examples considered, even higher precisions leading to significantly less than $\pm 20\mathrm{MeV}$ error bars for $L$ at 68% confidence level are necessary.

We present a new approach to investigate the evolution of collectivity on the nuclear map based on the ratio $R=B{(E2;2_1^{+}\to 0_1^{+})}_{exp}/B{(E2;2_1^{+}\to 0_1^{+})}_Q$, where the quantity in the denominator is calculated using the quadrupole moment of the $2_1^{+}$ level when known. The systematics of such ratios in even-even nuclei reveals interesting features including signatures for particular collective excitations and sensitivity to shell- and subshell closures. A reproduction of these data by theoretical models is highly desirable with the potential to shed more light on the interplay between collective and single-particle motions. In particular, a new signature for shape coexistence was found: $R<1$.

The scission point model has been used to calculate the total kinetic energy (TKE) as a function of fission fragments for photofission reactions. By comparing the calculated TKE values with the available experimental data, the deformation parameters of the fission fragments are obtained in the scission point model. The results show that the deformation parameters of the fission fragments have a large change near the symmetrical region. TKE distribution has been investigated for neutron-induced fission, spontaneous fission, and photofission to predict actinide TKE distribution. This indicates that the TKE distribution depends on the mass and atomic number of compound nuclei and, of course, the excitation energy. The odd-even effect plays an important role in predicting TKE distribution behavior. Also, TKE distribution has a similar trend for all isotopes and the TKE distribution of spontaneous fission is significantly different from the TKE distribution of photofission. At last, the total kinetic energy distributions for the photofission fragments of light actinides are evaluated in the scission point model.

The masses and decay widths of charmonium states are studied in the presence of strong magnetic fields. The mixing between the pseudoscalar and vector charmonium states at rest is observed to lead to appreciable negative (positive) shifts in the masses of the pseudoscalar (longitudinal component of the vector) charmonium states in vacuum as well as in hadronic medium in the presence of high magnetic fields. The pseudoscalar and vector charmonium masses in the hadronic medium, calculated in an effective chiral model from the medium changes of a scalar dilaton field, have additional significant modifications due to the mixing effects. The masses of the $D$ and $\overline{D}$ mesons in the magnetized hadronic matter are calculated within the chiral effective model. The partial decay widths of the vector charmonium state to $D\overline{D}$ are computed by using a field theoretical model for composite hadrons with quark and antiquark constituents and are compared with the decay widths calculated by using an effective hadronic Lagrangian. The effects of the mixing are observed to lead to significant contributions to the masses of the pseudoscalar and vector charmonium states, and an appreciable increase in the decay width $\psi \left(3770\right)\to D\overline{D}$ at large values of the magnetic fields. These studies of the charmonium states in strong magnetic fields should have observable consequences on the dilepton spectra, as well as on the production of the open charm mesons and the charmonium states in ultrarelativistic heavy ion collision experiments.

Background: Properties of proton-unbound ${}^{31}\mathrm{S}$ states determine the ${}^{30}\mathrm{P}(p,\gamma ){}^{31}\mathrm{S}$ reaction rate, which has a significant impact on explosive hydrogen burning in classical novae and type-I x-ray bursts. Despite several previous studies, uncertainties still remain with respect to the nuclear structure of ${}^{31}\mathrm{S}$ near the proton threshold.

Purpose: The level structure of ${}^{31}\mathrm{S}$ has been presently investigated via a charged-particle spectroscopy experiment using the ${}^{32}\mathrm{S}(p,d){}^{31}\mathrm{S}$ reaction.

Method: Deuterons corresponding to ${}^{31}\mathrm{S}$ excited states with $3.285\le E_x\le 10.8$ MeV were momentum analyzed via an Enge split-pole spectrograph at six laboratory angles between ${10}^{\circ }$ and ${62}^{\circ }$. Differential cross sections of the ${}^{32}\mathrm{S}(p,d){}^{31}\mathrm{S}$ reaction were measured at $E_p=34.5$ MeV. Distorted-wave Born approximation calculations were performed to constrain the spin-parity assignments of several of the observed levels.

Results: We have detected 72 excited states of ${}^{31}\mathrm{S}$, out of which 17 are within the astrophysical region of interest corresponding to the temperature range of 0.1–1.5 GK. We have resolved the discrepancy in the spin and parity of an excited state with $E_x=6542$ keV, showing that is it not $J^{\pi }=3/2^{-}$, and therefore the contribution of this state to the ${}^{30}\mathrm{P}(p,\gamma )$ reaction rate is likely much less significant than previously thought owing to the larger angular-momentum transfer required to populate this excited state. Moreover, our measurement results help consolidate the spin-parity assignments for the 6377 and 6636 keV states in ${}^{31}\mathrm{S}$.

Conclusions: This work presents the most comprehensive spin-parity assignments to date from a single-neutron transfer reaction on ${}^{32}\mathrm{S}$ to ${}^{31}\mathrm{S}$ excited states in the region between 6 to 7 MeV excitation energy. This region is significant for the determination of the ${}^{30}\mathrm{P}(p,\gamma ){}^{30}\mathrm{S}$ reaction rate over the temperatures characteristic of explosive hydrogen burning in novae.